[Pw_forum] IS DUAL CORE 2.7 GHz, 2GB RAM SUFFICIENT FOR QE calculations??

siddheshwar chopra sidhusai at gmail.com
Wed Jul 23 08:55:09 CEST 2014


Dear Ashkan,
Thats really sad news for me. :( I was planning to build a raspberry pi
cluster (with 512MB RAM on each board) for QE. But now it seems I might
waste my money making it.
Ashkan how about studying molecules with QE? As far as I read, we use 1x1x1
k-point (Gamma) only for studying them. Please give your comments on
molecule study. Say I need to study magnetic, optical and DOS of molecules.
Then is my system sufficient?

Regards,


On Wed, Jul 23, 2014 at 11:39 AM, ashkan shekaari <shekaari at gmail.com>
wrote:

> dear Siddheshwar
> i ran with 1,2, 8, 32, 48, 120 cores , but all had the same failed result.
>
> On 7/23/14, siddheshwar chopra <sidhusai at gmail.com> wrote:
> > Dear Ashkan,
> > I don't know if I am correct, but you could try reducing the number of
> > cores. This way I guess you will have more RAM to be used per core.
> >
> > Regards,
> >
> >
> > On Wed, Jul 23, 2014 at 10:47 AM, ashkan shekaari <shekaari at gmail.com>
> > wrote:
> >
> >> dear siddheshwar
> >>
> >> i ran a supercell system made of 48 atoms on a computer server with
> >> 120 cores and 6 GB of RAM , but it didn't work . my calculations
> >> failed , it needs more than 6 GB of RAM .
> >>
> >> On 7/23/14, siddheshwar chopra <sidhusai at gmail.com> wrote:
> >> > Dear Ashkan,
> >> > How much large RAM do you mean? Is it 4GB in total or more? I can add
> >> > another 2GB hence.
> >> >
> >> > Regards,
> >> >
> >> >
> >> > On Wed, Jul 23, 2014 at 6:50 AM, ashkan shekaari <shekaari at gmail.com>
> >> > wrote:
> >> >
> >> >> yes , but you can not run any supercell calculations or defected
> >> >> systems
> >> >> .
> >> >>
> >> >> for these calculations you should have a large amount of memory (RAM)
> >> >> .
> >> >>
> >> >> On 7/22/14, siddheshwar chopra <sidhusai at gmail.com> wrote:
> >> >> > Dear Users,
> >> >> > I am new to QE and really need an estimate about the computational
> >> >> > resources needed to run magnetic, phonon, optical and band
> structure
> >> >> > calculations for light, medium and heavy atoms of around 60 atoms
> >> >> > supercell. I currently have a dual core 2.7 GHz processor with 2GB
> >> RAM,
> >> >> > HDD=250GB. Please suggest me so that I can run calculations without
> >> any
> >> >> > memory of processor issues.
> >> >> > I have Windows XP and also Linux mint installed on the same
> machine.
> >> >> > I
> >> >> have
> >> >> > also increased the virtual memory per partition.
> >> >> > I also now how to make an external USB drive work as system RAM.
> >> >> > Will
> >> >> that
> >> >> > help me?
> >> >> >
> >> >> > Kind Regards,
> >> >> >
> >> >> > --
> >> >> > *Dr. Siddheshwar chopra,*
> >> >> >
> >> >> >
> >> >> > *M.Sc., Ph.D (Physics)Assistant Professor (Physics),*
> >> >> > *Amity University, Noida, India.*
> >> >> >
> >> >>
> >> >>
> >> >> --
> >> >> Best wishes
> >> >> Ashkan Shekaari
> >> >> _______________________________________________
> >> >> Pw_forum mailing list
> >> >> Pw_forum at pwscf.org
> >> >> http://pwscf.org/mailman/listinfo/pw_forum
> >> >>
> >> >
> >> >
> >> >
> >> > --
> >> > *Dr. Siddheshwar chopra,*
> >> >
> >> >
> >> > *M.Sc., Ph.D (Physics)Assistant Professor (Physics),*
> >> > *Amity University, Noida, India.*
> >> >
> >>
> >>
> >> --
> >> Best wishes
> >> Ashkan Shekaari
> >> _______________________________________________
> >> Pw_forum mailing list
> >> Pw_forum at pwscf.org
> >> http://pwscf.org/mailman/listinfo/pw_forum
> >>
> >
> >
> >
> > --
> > *Dr. Siddheshwar chopra,*
> >
> >
> > *M.Sc., Ph.D (Physics)Assistant Professor (Physics),*
> > *Amity University, Noida, India.*
> >
>
>
> --
> Best wishes
> Ashkan Shekaari
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>



-- 
*Dr. Siddheshwar chopra,*


*M.Sc., Ph.D (Physics)Assistant Professor (Physics),*
*Amity University, Noida, India.*
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